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authorRichard Henderson <richard.henderson@linaro.org>2021-03-15 14:40:04 -0600
committerLaurent Vivier <laurent@vivier.eu>2021-04-07 18:55:27 +0200
commit360f0abdc51652b06a3718ed43a8688562e69ca4 (patch)
tree1cabb7f09d56175334301eca8ae26a7b888b1c56
parentd0d3dd401b70168a353450e031727affee828527 (diff)
downloadqemu-arm-360f0abdc51652b06a3718ed43a8688562e69ca4.tar.gz
linux-user: Use signed lengths in uaccess.c
Partially revert 09f679b62dff, but only for the length arguments. Instead of reverting to long, use ssize_t. Reinstate the > 0 check in unlock_user. Fixes: 09f679b62dff Reported-by: Coverity (CID 1446711) Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20210315204004.2025219-1-richard.henderson@linaro.org> [lv: remove superfluous semicolon] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
-rw-r--r--linux-user/qemu.h15
-rw-r--r--linux-user/uaccess.c12
2 files changed, 15 insertions, 12 deletions
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 52c981710b..74e06e7121 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -627,8 +627,8 @@ static inline bool access_ok(CPUState *cpu, int type,
* buffers between the target and host. These internally perform
* locking/unlocking of the memory.
*/
-int copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
-int copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
+int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
+int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);
/* Functions for accessing guest memory. The tget and tput functions
read/write single values, byteswapping as necessary. The lock_user function
@@ -638,16 +638,19 @@ int copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
/* Lock an area of guest memory into the host. If copy is true then the
host area will have the same contents as the guest. */
-void *lock_user(int type, abi_ulong guest_addr, size_t len, bool copy);
+void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy);
/* Unlock an area of guest memory. The first LEN bytes must be
flushed back to guest memory. host_ptr = NULL is explicitly
allowed and does nothing. */
#ifndef DEBUG_REMAP
-static inline void unlock_user(void *host_ptr, abi_ulong guest_addr, size_t len)
-{ }
+static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
+ ssize_t len)
+{
+ /* no-op */
+}
#else
-void unlock_user(void *host_ptr, abi_ulong guest_addr, long len);
+void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len);
#endif
/* Return the length of a string in target memory or -TARGET_EFAULT if
diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c
index c696913016..6a5b029607 100644
--- a/linux-user/uaccess.c
+++ b/linux-user/uaccess.c
@@ -4,7 +4,7 @@
#include "qemu.h"
-void *lock_user(int type, abi_ulong guest_addr, size_t len, bool copy)
+void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy)
{
void *host_addr;
@@ -24,7 +24,7 @@ void *lock_user(int type, abi_ulong guest_addr, size_t len, bool copy)
}
#ifdef DEBUG_REMAP
-void unlock_user(void *host_ptr, abi_ulong guest_addr, size_t len);
+void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len)
{
void *host_ptr_conv;
@@ -35,7 +35,7 @@ void unlock_user(void *host_ptr, abi_ulong guest_addr, size_t len);
if (host_ptr == host_ptr_conv) {
return;
}
- if (len != 0) {
+ if (len > 0) {
memcpy(host_ptr_conv, host_ptr, len);
}
g_free(host_ptr);
@@ -48,14 +48,14 @@ void *lock_user_string(abi_ulong guest_addr)
if (len < 0) {
return NULL;
}
- return lock_user(VERIFY_READ, guest_addr, (size_t)len + 1, 1);
+ return lock_user(VERIFY_READ, guest_addr, len + 1, 1);
}
/* copy_from_user() and copy_to_user() are usually used to copy data
* buffers between the target and host. These internally perform
* locking/unlocking of the memory.
*/
-int copy_from_user(void *hptr, abi_ulong gaddr, size_t len)
+int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len)
{
int ret = 0;
void *ghptr = lock_user(VERIFY_READ, gaddr, len, 1);
@@ -69,7 +69,7 @@ int copy_from_user(void *hptr, abi_ulong gaddr, size_t len)
return ret;
}
-int copy_to_user(abi_ulong gaddr, void *hptr, size_t len)
+int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len)
{
int ret = 0;
void *ghptr = lock_user(VERIFY_WRITE, gaddr, len, 0);